My U.S. Pat. No. 5,435,281 which issued on Jul. 25, 1995 discloses a cylinder head for an internal combustion engine with a base component formed from iron for providing the upper end of the combustion chamber, the intake and exhaust ports and support for the intake and exhaust valves, fuel injector or spark plug. A one-piece tappet and camshaft carrier made of aluminum alloy is attached to the base and includes open lattice work of interconnected segments to support the tappets for operation therein and camshaft supporting bulkheads integral with the lattice work. The bulkheads are spaced and interconnected by the lattice work that includes thermal expansion and contraction joints located so that the wide range of temperature variations occurring during engine operation does not cause damage to the lattice work or the bulkheads.
Another support-frame construction devised as a tappet and camshaft carrier for attachment to a base portion of an internal combustion engine's cylinder head can be seen in U.S. Pat. No. 5,080,057 issued on Jan. 14, 1992 in the name of Batzill et al. The Batzill et al. patent is directed to a die cast and machined carrier comprising upper and lower sections secured to a cylinder head housing. When installed, the two-part carrier forms a web-like structure of ribs, struts and annular sections for receiving and slidably supporting inverted bucket tappets of the intake and exhaust valves and for rotatably supporting the camshafts above the tappets. This multi-part carrier provides a cylinder head assembly of high rigidity with the camshaft and tappets operatively mounted thereon. However, a thermal expansion or contraction function is not provided by the Batzill et al. carrier.